docs: def _compute_magnitude_scaling(self, rup, C):
          """
          Compute magnitude-scaling term, equations (5a) and (5b), pag 107.
          """
          U, SS, NS, RS = self._get_fault_type_dummy_variables(rup)
          if rup.mag <= C['Mh']:
              return C['e1'] * U + C['e2'] * SS + C['e3'] * NS + C['e4'] * RS + \
                  C['e5'] * (rup.mag - C['Mh']) + \
                  C['e6'] * (rup.mag - C['Mh']) ** 2
          else:
              return C['e1'] * U + C['e2'] * SS + C['e3'] * NS + C['e4'] * RS + \
                  C['e7'] * (rup.mag - C['Mh'])